Pediatric hepatic imaging

Prenatal diagnosis and treatment of intrahepatic arteriovenous fistulas: case reports and the literature review

Background: Congenital arteriovenous intrahepatic fistulas, which are hepatic hemangiomas and arteriovenous malformations (AVMs) are rare and they confused with each other. Knowledge of prenatal medical treatment of AVMs is insufficient.Objectives: First is to emphasize the distinction between hepatic hemangioma and AVMs. Second is discussion of the first case of hepatic AVM that responded well to steroid-propranolol treatment in the prenatal period.Methods: Color Doppler ultrasonography, fetal and postnatal MR were used for diagnosis.Results: The first case is a giant hepatic hemangioma diagnosed and progressively growing in the prenatal period and gradually shrinking in the postnatal period. The second case was hepatic AVM with no signs of heart failure during the prenatal period and postnatal right extended hepatectomy was performed as the anastomosis was enlarged and intraportal collateral vessels were developed. The third case is the first hepatic AVM which reaches a term that was prenatally diagnosed and responded to treatment with marked reduction.Conclusion: Color flow and pulse Doppler imaging have a key role in the prenatal diagnosis of arteriovenous fistulas. Intrahepatic AVM are abnormal intrahepatic vascular network formation primarily fed by the hepatic artery or its branches and drained by the hepatic venous system. This vascular region looks like a mass, but it does not contain a solid area, which allows the separation of hepatic AVMs from hepatic hemangiomas. Steroid and propranolol therapy should be considered in management.

Imaging of Rare Primary Malignant Hepatic Tumors in Adults With Histopathological Correlation

Hepatocellular carcinoma and cholangiocarcinoma are the most common primary liver malignancies in adults (comprising >85%); however, liver is also host to some unusual primary malignant tumors. Some of these tumors show distinct demographic, clinicopathologic, and imaging features. Imaging features of these uncommon primary malignant liver tumors are presented with an attempt to correlate them with histopathology.

Prenatal diagnosis of a liver cavernous hemangioma

Liver tumors seldom occur in the perinatal period. Hepatic hemangiomas are the most common tumors of the liver diagnosed during fetal and neonatal life. The diagnosis can be suspected antenatally by ultrasound and MR scan. The differential diagnosis is often challenging. While small hepatic hemangiomas are usually asymptomatic, large tumors can lead to complications such as high-output congestive heart failure, consumptive thrombocytopenic coagulopathy and hemorrhage after tumor rupture. We describe a case of hepatic hemangioma presenting as a solid abdominal mass with several cystic areas on an obstetric ultrasound and report on the contribition fetal MR imaging to the diagnosis.

Hepatobiliary tumors

The investigation of hepatobiliary tumors, in the pediatric population, usually begins with an ultrasonographic (US) examination. It is readily available without ionizing radiation and does not need sedation. Therefore US is an outstanding imaging modality for screening and follow-up. Doppler and color Doppler interrogation are part of the examination to assess vascularity of the lesions and vascular anatomy. Magnetic resonance imaging is a comprehensive imaging modality with multiplanar capability to assess the liver parenchyma, gallbladder, and biliary tree and is free of ionizing radiation. This article highlights the current status of imaging of the most common hepatobiliary tumors in children.

Impact of virtual imaging procedures on treatment strategies in children with hepatic vascular malformations

OBJECTIVES

Virtual imaging procedures have only rarely been analyzed in pediatric populations. We evaluated the role of CT-based virtual surgery planning in pediatric patients experiencing hepatic vascular malformations (HVM).

METHODS

We analyzed 12 children with complex hepatic vascular malformations. All of the children received multislice CT scans with contrast medium followed by virtual 3-dimensional reconstructions using the software assistants MeVis LiverAnalyzer and MeVis LiverExplorer. The impact on treatment planning and the correspondence to clinical findings was assessed.

RESULTS

Highest accuracies of virtual data were found in cases of intrahepatic portocaval shunt and persistent ductus venosus. Here, virtual data revealed congenital vascular conditions, which were not always seen using standard imaging diagnostics. In some patients with portalvenous thrombosis, virtual imaging provided important contributions to determining the feasibility of different shunt procedures. However, in some patients experiencing portalvenous thrombosis or liver diffuse hemangioma, virtual methods were not as accurate as standard diagnostic procedures. Nevertheless, these tools facilitated simultaneous and continuous illustrations of the different vascular systems.

CONCLUSIONS

Virtual imaging and planning procedures had an important impact on treatment strategies and outcomes in children with HVM. Their use as standard diagnostic tools in selected cases of HVM should be considered.

Imaging of paediatric liver tumours with pathological correlation

Paediatric hepatic tumours are relatively rare with malignant lesions being twice as frequent as benign neoplasms and are mostly metastases. Imaging has a significant role in the evaluation of most paediatric liver tumours. Differentiating benign from malignant tumours is important as it significantly affects treatment decisions. We present the characteristic radiological and pathological features of the most common paediatric liver tumours.

Pediatric liver: focal masses

Imaging is a standard part of the evaluation of pediatric liver disease. Advances in MR imaging have improved detection, characterization, and staging of hepatic lesions. This article addresses the MR imaging appearances of various focal hepatic lesions that can present in children. Techniques for performing hepatic MR imaging also are reviewed.

Imaging of focal hepatic lesions: self-assessment module

Focal hepatic lesions are one of the diagnostic challenges in daily practice. This article focuses on the imaging features of focal hepatic lesions on different imaging modalities, including sonography, CT, and MRI.

Hepatic Mesenchymal Hamartoma Combined with Infantile Hepatic Hemangioendothelioma in an Infant

Hepatic mesenchymal hamartoma is a rare benign tumor in children, and infantile hepatic hemangioendothelioma is also a rare liver neoplasm. We report a female newborn with an abdominal mass noted by the regular maternal ultrasound at 32 weeks of gestation. After birth, a liver mass was detected by computed tomography and magnetic resonance cholangiopancreatography. Frequent postprandial vomiting and progressive abdominal distension occurred 4 months later. Three tumor masses were detected this time, and the serum alpha-fetoprotein (AFP) was 6700 ng/mL. Segmental resection was performed initially and complete resection of these tumors and left lobectomy were performed 21 days later. Pathologic examination of these liver masses revealed mesenchymal hamartoma combined with infantile hepatic hemangioendothelioma. After half a year of regular follow-up, the AFP level decreased gradually to 79.5 ng/mL, without evidence of tumor recurrence.

Estudo de 50 casos por tomografia computadorizada de lesões hipodensas hepáticas fundamentais na infância

OBJETIVO: Relatar os diferentes aspectos tomográficos das lesões hepáticas hipodensas na infância, orientando às diferentes possibilidades diagnósticas. MATERIAIS E MÉTODOS: Foram realizados estudos tomográficos de lesões hipodensas hepáticas previamente diagnosticadas à ultra-sonografia em 50 pacientes pediátricos (0-16 anos). As imagens foram obtidas antes e após a administração de contraste venoso. Os aspectos de imagem foram analisados e correlacionados posteriormente com o diagnóstico anatomopatológico. RESULTADOS: Dos 50 casos estudados, 47 foram confirmados, 30 destes por estudo anatomopatológico. A maioria das lesões era benigna, sendo o hemangioma o mais freqüente (20% dos casos). Tais lesões apresentaram captação homogênea do meio de contraste, principalmente na fase tardia, diferenciando assim das malignas. As lesões malignas mais freqüentes foram as metástases (18%). CONCLUSÃO: O presente estudo constatou que o exame tomográfico, antes e após a administração do contraste venoso, dinâmico e/ou helicoidal, foi de grande valia para a complementação da hipótese diagnóstica nas lesões hipodensas hepáticas na infância, devendo ser rotina após diagnóstico ultra-sonográfico.

Pediatric liver magnetic resonance imaging

Imaging is a standard part of the evaluation of pediatric liver disease. Advances in MR imaging have improved the detection, characterization, and staging of hepatic lesions. Clinical information, however, is still important in selecting the best imaging study and in correctly interpreting the examination. This article addresses the clinical and imaging features of the common hepatic and biliary lesions in children. In addition, the techniques for performing hepatic MR imaging are reviewed.

MR imaging of the pediatric liver

Applications of MR imaging of the pediatric abdomen are expanding rapidly. New techniques of MR imaging, such as MRA or MRCP, are becoming commonplace. MR imaging is particularly helpful in the diagnosis and characterization of liver and biliary tree disease in children. Consistent and reproducible quality imaging is achieved with faster imaging sequences tailored to reduce motion artifacts. The lack of radiation, the ability to directly acquire multiple imaging planes, and the superior contrast resolution, particularly with the administration of gadolinium, have contributed to the acceptance of MR imaging as an invaluable tool in the pediatric age group.

Unique imaging issues in pediatric liver disease

In many clinical scenarios, liver imaging does not differ as greatly in children as in adults. Common indications for liver imaging in children include trauma, suspected mass, pre-transplantation studies, monitoring after liver transplantation, jaundice, or liver dysfunction. This article highlights areas in which pathology or imaging approach in children differs from that seen in adults. Topics covered include imaging of a suspected hepatic mass, neonatal jaundice, and segmental liver transplantation.

Sarcoma embrionário indiferenciado do fígado: relato de caso

O sarcoma embrionário indiferenciado do fígado é uma entidade rara que acomete, principalmente, crianças acima dos cinco anos de idade. O aspecto macroscópico consiste, caracteristicamente, de grande massa hepática com maior componente sólido, porém apresenta algumas áreas císticas. Curiosamente, a tomografia computadorizada superestima o componente cístico da lesão, sendo a ultra-sonografia um método mais fidedigno na demonstração da consistência do tumor. Os estudos por imagem ajudam a afastar enfermidades não-neoplásicas, como abscessos e hematomas hepáticos, e avaliam a extensão das lesões. O diagnóstico de sarcoma embrionário indiferenciado pode ser corretamente presumido quando se consideram os achados de imagem em conjunto com a idade do paciente e o nível de alfa-fetoproteína. Os autores descrevem um caso de sarcoma embrionário indiferenciado no fígado de uma criança do sexo feminino de dez anos de idade, enfatizando seus aspectos imagenológicos e o diagnóstico diferencial.

Sonographic diagnosis of subcapsular liver hematoma mimicking tumor in a neonate

Subcapsular hematomas of the liver in neonates uncommonly present as an abdominal mass without clinical signs of bleeding. We report a case in which sonography 10 days after birth demonstrated 2 large hepatic lesions that were initially considered to be tumors. The diagnosis of subcapsular liver hematoma was es tablished by serial ultrasound examinations, which demonstrated rapid diminution of the lesions. A history of difficult umbilical venous catheter insertion was then obtained retrospectively.

US approach to jaundice in infants and children

High-resolution real-time ultrasonography (US) serves as an important tool for differentiation of obstructive and nonobstructive causes of jaundice in infants and children, independent of liver function. Unconjugated hyperbilirubinemia occurs in approximately 60% of normal term infants and in 80% of preterm infants. Persistence of neonatal jaundice beyond 2 weeks of age demands US evaluation to differentiate between the three most common causes: hepatitis, biliary atresia, and choledochal cyst. In all three conditions, the hepatic echotexture is diffusely coarse and hyperechoic, but this appearance may be seen in a variety of hepatic inflammatory, obstructive, and metabolic processes. Thus, hepatic scintigraphy and at times percutaneous liver biopsy are necessary to narrow the differential diagnosis and to identify patients who require more invasive techniques (eg, intraoperative cholangiography). US is useful for demonstrating inspissated bile and biliary duct stones. In infants, stones are usually secondary to obstructive congenital anomalies of the biliary tract, total parenteral nutrition, furosemide treatment, phototherapy, dehydration, infection, hemolytic anemia, and short-gut syndrome, whereas in older children, stones are usually associated with sickle cell disease, bowel resection, hemolytic anemia, and choledochal cyst. Jaundice in infants and children may also be due to cirrhosis, benign strictures, and neoplastic processes.